Oohhh, that does not have a simple answer.
Sort of, white plymouth rock and white cornish, I believe.
But you will not get a typical Cornish X like the chicks sold for meat from buying these two breeds and mating them, even assuming I have it right. There are years and years of patented breeding involved in producing those chicks. And they are not the same from all sources. Hopefully some others who know more about breeds and genetics will chime in here.